Switchblade in California laws?

I want to buy an Italian stiletto, I know switchblades are illegal in California, if the blade is over 2 inches. But I don't understand the law fully. Are they illegal to have even at home? If not, where could I carry it? If I have a belt holster is it still illegal? Even though it is not concealed? And what would be the penalty for being caught with one in your possession? Thank you!